| With the gradual improvement of the steel production process, high strength steel is more and more applied to the building structure. There are obvious differences in the aspects of material mechanical properties, production process and the influence of initial imperfection between the ordinary strength steel and the high strength steel, and the overall buckling behavior is also different. The existing design specifications are based on the experimental and theoretical study of the ordinary strength steel structure,and there is no mature calculation theory and design method for the mechanical properties of high strength steel structure. In this paper, we used a combination of experimental research, numerical simulation and theoretical analysis, studied the overall buckling behavior of axially compressed welded H-section columns made of Q460 high strength steel systematically, and the main research contents and results are as follows:(1)It measured the residual stress distribution of 6 Q460 welded H-section short columns(cutting edge) by blind-hold method, and get the residual stress distribution rules of this cross section, and analyzed the influence of plate width thickness ratio and thickness on the residual stress distribution, at the same time, put forward the corresponding distribution model and calculation method.(2)We made axial compression test of 6 Q460 high strength steel welded H-section columns. The test results showed that the integral stability coefficient of these components were significantly higher than the column curves specified by Chinese code and Eurocode3, and the calculation results were close to ANSI/AISC360-10, it was necessary to correct or raise new column curves for high strength steelcomponents.(3)The finite element model considering the initial imperfections simulated the overall stability of Q460 axial compression member effectively.The ultimate bearing capacity calculation of different sectional dimensions and slenderness had a high accuracy.(4)Several main parameters that influenced the overall buckling behavior of the axial compression column were analyzed. Based on the existing Chinese code and Eurocode3 design method, we refit the column curves and modified the calculation parameter, put forward a new design methods which was more suitable for practical engineering. Through the comparison with experimental results, we know that, the new column curve could reflect the change trend of the overall stability of the axial compression coefficient very well, this design method could predict the stable bearing capacity of this component effectively. |
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